Jargon Buster — Rastor or Vector Images

Jargon Buster - Rastor or Vector

Ever heard designers talking about vector and raster image formats? Ever had someone request a specific file type and wondered why?

This short article explains the differences and when/where you should use each one.

Vector or Raster

Raster Images

A raster graphic is an image made up of multiple tiny squares of colour information, mostly known as either pixels or dots*. Raster graphics are wonderful for rich, full-colour images such as photographs.

Most used raster file types: .jpg, .png, .gif, .bmp, .tiff

Advantages

Raster graphics are great when creating rich and detailed images. Every pixel in a raster image can be a different colour therefore you can create a complex image with all kinds of colour changes and variations.

The most recognised program that handles raster graphics is Adobe Photoshop however there are also several other image editing software options out there for you to choose from. Almost any program can work with a simple raster file.

Disadvantages

Raster images cannot be scaled up in size very well. If you do try to enlarge a raster image, it will look grainy and pixellated. This is because raster images are created with a finite number of pixels. When you enlarge a photo, the computer takes its best guess as to what specific colours should fill in the gaps. The photo editing software that you are using will try to fill these gaps the best they can however, the resulting image is often blurry.

As each individual pixel contains a lot of information, including colours and X & Y co-ordinates, raster images are quite large. The amount of data can also mean they are slower to edit.

Vector or Raster

Vector Images

Vector graphics are based on mathematical formulas to draw shapes and paths. A vector graphic is made up of a series of small points that combine together to make lines and images. Vector graphics are brilliant for creating illustrations, logos and icons.

Most used raster file types: .eps, .ai, .svg, .dxf, .pdf

Advantages

Vector files can be scaled up or down as much as you want without losing any image quality. Vector images simply use the mathematic equation from the points to create a consistent shape every time.

As there is less data stored in a vector image they are normally a lot smaller and faster to load.

Vectors are easier to edit as they are not “flattened” and are capable of having multiple layers for individual editing. This is called non destructive working and can save a lot of time.

Disadvantages

The mathematical way vector images are formed, limits the colour complexity and depth. Therefore the image is normally very flat or uses basic gradients.

Vector graphics are so precise that a small error will be easily noticeable when enlarged significantly.

Vector or Raster

So which one should I use?

If you’re using a photograph or other image with lots of colour detail, go with Raster. For Logos, fonts, icons and simple coloured illustrations, choose Vector. Simple!

If you’re still having trouble, get in touch about our design services.

*Dots & Pixels

Whilst we’re on the subject. Pixels are commonly used when dealing with digital media, however, dots are used when it comes to print. This can cause some confusion when it comes to DPI (Dots per Inch) & PPI (Pixels per Inch). Just remember if it’s on a screen use pixels.